<?php

if (!defined('BASEPATH'))
    exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */
// ------------------------------------------------------------------------

/**
 * Common Functions
 *
 * Loads the base classes and executes the request.
 *
 * @package		CodeIgniter
 * @subpackage	codeigniter
 * @category	Common Functions
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/
 */
// ------------------------------------------------------------------------

/**
 * Determines if the current version of PHP is greater then the supplied value
 *
 * Since there are a few places where we conditionally test for PHP > 5
 * we'll set a static variable.
 *
 * @access	public
 * @param	string
 * @return	bool	TRUE if the current version is $version or higher
 */
if (!function_exists('is_php')) {

    function is_php($version = '5.0.0') {
        static $_is_php;
        $version = (string) $version;

        if (!isset($_is_php[$version])) {
            $_is_php[$version] = (version_compare(PHP_VERSION, $version) < 0) ? FALSE : TRUE;
        }

        return $_is_php[$version];
    }

}

// ------------------------------------------------------------------------

/**
 * Tests for file writability
 *
 * is_writable() returns TRUE on Windows servers when you really can't write to
 * the file, based on the read-only attribute.  is_writable() is also unreliable
 * on Unix servers if safe_mode is on.
 *
 * @access	private
 * @return	void
 */
if (!function_exists('is_really_writable')) {

    function is_really_writable($file) {
        // If we're on a Unix server with safe_mode off we call is_writable
        if (DIRECTORY_SEPARATOR == '/' AND @ini_get("safe_mode") == FALSE) {
            return is_writable($file);
        }

        // For windows servers and safe_mode "on" installations we'll actually
        // write a file then read it.  Bah...
        if (is_dir($file)) {
            $file = rtrim($file, '/') . '/' . md5(mt_rand(1, 100) . mt_rand(1, 100));

            if (($fp = @fopen($file, FOPEN_WRITE_CREATE)) === FALSE) {
                return FALSE;
            }

            fclose($fp);
            @chmod($file, DIR_WRITE_MODE);
            @unlink($file);
            return TRUE;
        } elseif (!is_file($file) OR ($fp = @fopen($file, FOPEN_WRITE_CREATE)) === FALSE) {
            return FALSE;
        }

        fclose($fp);
        return TRUE;
    }

}

// ------------------------------------------------------------------------

/**
 * Class registry
 *
 * This function acts as a singleton.  If the requested class does not
 * exist it is instantiated and set to a static variable.  If it has
 * previously been instantiated the variable is returned.
 *
 * @access	public
 * @param	string	the class name being requested
 * @param	string	the directory where the class should be found
 * @param	string	the class name prefix
 * @return	object
 */
if (!function_exists('load_class')) {

    function &load_class($class, $directory = 'libraries', $prefix = 'CI_') {
        static $_classes = array();

        // Does the class exist?  If so, we're done...
        if (isset($_classes[$class])) {
            return $_classes[$class];
        }

        $name = FALSE;

        // Look for the class first in the local application/libraries folder
        // then in the native system/libraries folder
        foreach (array(APPPATH, BASEPATH) as $path) {
            if (file_exists($path . $directory . '/' . $class . '.php')) {
                $name = $prefix . $class;

                if (class_exists($name) === FALSE) {
                    require($path . $directory . '/' . $class . '.php');
                }

                break;
            }
        }

        // Is the request a class extension?  If so we load it too
        if (file_exists(APPPATH . $directory . '/' . config_item('subclass_prefix') . $class . '.php')) {
            $name = config_item('subclass_prefix') . $class;

            if (class_exists($name) === FALSE) {
                require(APPPATH . $directory . '/' . config_item('subclass_prefix') . $class . '.php');
            }
        }

        // Did we find the class?
        if ($name === FALSE) {
            // Note: We use exit() rather then show_error() in order to avoid a
            // self-referencing loop with the Excptions class
            exit('Unable to locate the specified class: ' . $class . '.php');
        }

        // Keep track of what we just loaded
        is_loaded($class);

        $_classes[$class] = new $name();
        return $_classes[$class];
    }

}

// --------------------------------------------------------------------

/**
 * Keeps track of which libraries have been loaded.  This function is
 * called by the load_class() function above
 *
 * @access	public
 * @return	array
 */
if (!function_exists('is_loaded')) {

    function is_loaded($class = '') {
        static $_is_loaded = array();

        if ($class != '') {
            $_is_loaded[strtolower($class)] = $class;
        }

        return $_is_loaded;
    }

}

// ------------------------------------------------------------------------

/**
 * Loads the main config.php file
 *
 * This function lets us grab the config file even if the Config class
 * hasn't been instantiated yet
 *
 * @access	private
 * @return	array
 */
if (!function_exists('get_config')) {

    function &get_config($replace = array()) {
        static $_config;

        if (isset($_config)) {
            return $_config[0];
        }

        // Is the config file in the environment folder?
        if (!defined('ENVIRONMENT') OR !file_exists($file_path = APPPATH . 'config/' . ENVIRONMENT . '/config.php')) {
            $file_path = APPPATH . 'config/config.php';
        }

        // Fetch the config file
        if (!file_exists($file_path)) {
            exit('The configuration file does not exist.');
        }

        require($file_path);

        // Does the $config array exist in the file?
        if (!isset($config) OR !is_array($config)) {
            exit('Your config file does not appear to be formatted correctly.');
        }

        // Are any values being dynamically replaced?
        if (count($replace) > 0) {
            foreach ($replace as $key => $val) {
                if (isset($config[$key])) {
                    $config[$key] = $val;
                }
            }
        }

        return $_config[0] = & $config;
    }

}

// ------------------------------------------------------------------------

/**
 * Returns the specified config item
 *
 * @access	public
 * @return	mixed
 */
if (!function_exists('config_item')) {

    function config_item($item) {
        static $_config_item = array();

        if (!isset($_config_item[$item])) {
            $config = & get_config();

            if (!isset($config[$item])) {
                return FALSE;
            }
            $_config_item[$item] = $config[$item];
        }

        return $_config_item[$item];
    }

}

// ------------------------------------------------------------------------

/**
 * Error Handler
 *
 * This function lets us invoke the exception class and
 * display errors using the standard error template located
 * in application/errors/errors.php
 * This function will send the error page directly to the
 * browser and exit.
 *
 * @access	public
 * @return	void
 */
if (!function_exists('show_error')) {

    function show_error($message, $status_code = 500, $heading = 'An Error Was Encountered') {
        $_error = & load_class('Exceptions', 'core');
        echo $_error->show_error($heading, $message, 'error_general', $status_code);
        exit;
    }

}

// ------------------------------------------------------------------------

/**
 * 404 Page Handler
 *
 * This function is similar to the show_error() function above
 * However, instead of the standard error template it displays
 * 404 errors.
 *
 * @access	public
 * @return	void
 */
if (!function_exists('show_404')) {

    function show_404($page = '', $log_error = TRUE) {
        $_error = & load_class('Exceptions', 'core');
        $_error->show_404($page, $log_error);
        exit;
    }

}

// ------------------------------------------------------------------------

/**
 * Error Logging Interface
 *
 * We use this as a simple mechanism to access the logging
 * class and send messages to be logged.
 *
 * @access	public
 * @return	void
 */
if (!function_exists('log_message')) {

    function log_message($level = 'error', $message, $php_error = FALSE) {
        static $_log;

        if (config_item('log_threshold') == 0) {
            return;
        }

        $_log = & load_class('Log');
        $_log->write_log($level, $message, $php_error);
    }

}

// ------------------------------------------------------------------------

/**
 * Set HTTP Status Header
 *
 * @access	public
 * @param	int		the status code
 * @param	string
 * @return	void
 */
if (!function_exists('set_status_header')) {

    function set_status_header($code = 200, $text = '') {
        $stati = array(
            200 => 'OK',
            201 => 'Created',
            202 => 'Accepted',
            203 => 'Non-Authoritative Information',
            204 => 'No Content',
            205 => 'Reset Content',
            206 => 'Partial Content',
            300 => 'Multiple Choices',
            301 => 'Moved Permanently',
            302 => 'Found',
            304 => 'Not Modified',
            305 => 'Use Proxy',
            307 => 'Temporary Redirect',
            400 => 'Bad Request',
            401 => 'Unauthorized',
            403 => 'Forbidden',
            404 => 'Not Found',
            405 => 'Method Not Allowed',
            406 => 'Not Acceptable',
            407 => 'Proxy Authentication Required',
            408 => 'Request Timeout',
            409 => 'Conflict',
            410 => 'Gone',
            411 => 'Length Required',
            412 => 'Precondition Failed',
            413 => 'Request Entity Too Large',
            414 => 'Request-URI Too Long',
            415 => 'Unsupported Media Type',
            416 => 'Requested Range Not Satisfiable',
            417 => 'Expectation Failed',
            500 => 'Internal Server Error',
            501 => 'Not Implemented',
            502 => 'Bad Gateway',
            503 => 'Service Unavailable',
            504 => 'Gateway Timeout',
            505 => 'HTTP Version Not Supported'
        );

        if ($code == '' OR !is_numeric($code)) {
            show_error('Status codes must be numeric', 500);
        }

        if (isset($stati[$code]) AND $text == '') {
            $text = $stati[$code];
        }

        if ($text == '') {
            show_error('No status text available.  Please check your status code number or supply your own message text.', 500);
        }

        $server_protocol = (isset($_SERVER['SERVER_PROTOCOL'])) ? $_SERVER['SERVER_PROTOCOL'] : FALSE;

        if (substr(php_sapi_name(), 0, 3) == 'cgi') {
            header("Status: {$code} {$text}", TRUE);
        } elseif ($server_protocol == 'HTTP/1.1' OR $server_protocol == 'HTTP/1.0') {
            header($server_protocol . " {$code} {$text}", TRUE, $code);
        } else {
            header("HTTP/1.1 {$code} {$text}", TRUE, $code);
        }
    }

}

// --------------------------------------------------------------------

/**
 * Exception Handler
 *
 * This is the custom exception handler that is declaired at the top
 * of Codeigniter.php.  The main reason we use this is to permit
 * PHP errors to be logged in our own log files since the user may
 * not have access to server logs. Since this function
 * effectively intercepts PHP errors, however, we also need
 * to display errors based on the current error_reporting level.
 * We do that with the use of a PHP error template.
 *
 * @access	private
 * @return	void
 */
if (!function_exists('_exception_handler')) {

    function _exception_handler($severity, $message, $filepath, $line) {
        // We don't bother with "strict" notices since they tend to fill up
        // the log file with excess information that isn't normally very helpful.
        // For example, if you are running PHP 5 and you use version 4 style
        // class functions (without prefixes like "public", "private", etc.)
        // you'll get notices telling you that these have been deprecated.
        if ($severity == E_STRICT) {
            return;
        }

        $_error = & load_class('Exceptions', 'core');

        // Should we display the error? We'll get the current error_reporting
        // level and add its bits with the severity bits to find out.
        if (($severity & error_reporting()) == $severity) {
            $_error->show_php_error($severity, $message, $filepath, $line);
        }

        // Should we log the error?  No?  We're done...
        if (config_item('log_threshold') == 0) {
            return;
        }

        $_error->log_exception($severity, $message, $filepath, $line);
    }

}

// --------------------------------------------------------------------

/**
 * Remove Invisible Characters
 *
 * This prevents sandwiching null characters
 * between ascii characters, like Java\0script.
 *
 * @access	public
 * @param	string
 * @return	string
 */
if (!function_exists('remove_invisible_characters')) {

    function remove_invisible_characters($str, $url_encoded = TRUE) {
        $non_displayables = array();

        // every control character except newline (dec 10)
        // carriage return (dec 13), and horizontal tab (dec 09)

        if ($url_encoded) {
            $non_displayables[] = '/%0[0-8bcef]/'; // url encoded 00-08, 11, 12, 14, 15
            $non_displayables[] = '/%1[0-9a-f]/'; // url encoded 16-31
        }

        $non_displayables[] = '/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]+/S'; // 00-08, 11, 12, 14-31, 127

        do {
            $str = preg_replace($non_displayables, '', $str, -1, $count);
        } while ($count);

        return $str;
    }

}

// ------------------------------------------------------------------------

/**
 * Returns HTML escaped variable
 *
 * @access	public
 * @param	mixed
 * @return	mixed
 */
if (!function_exists('html_escape')) {

    function html_escape($var) {
        if (is_array($var)) {
            return array_map('html_escape', $var);
        } else {
            return htmlspecialchars($var, ENT_QUOTES, config_item('charset'));
        }
    }

}

/* End of file Common.php */
/* Location: ./system/core/Common.php */